The primary objectives of this research program are 1) to obtain information on the effect of adrenal cortical insufficiency on the chemical composition of inner ear fluids and morphology of the inner ear tissues, 2) to determine the dose and time course of the administration of adrenal hormones which would result in normalization of the inner ear fluid chemistry and temporal bone pathology and 3) provide necessary information for establishing guidelines for clinical treatment. We hope to accomplish these objectives by setting up an animal model where the adrenal cortical insufficiency has been produced experimentally and by studying longitudinally the auditory and vestibular function of human subjects with adrenal cortical insufficiency under controlled programs of hormonal treatment. It is hoped that this study will provide more understanding of the biochemical mechanisms of functional disturbance of the auditory and vestibular organs in adrenal cortical insufficiency and provide a rationale for the development of therapeutic management.